Why is Amazon Location Service showing $0 usage and only ~100 requests after geocoding 141,000 addresses?

Thank you for your question about Amazon Location Service (ALS) usage and billing. There are a few factors that could explain what you're experiencing:

1. Free Tier: Amazon Location Service offers a free tier that includes 20,000 Geocode requests per month for the first three months. If your AWS account is within this initial period, you may not see charges for your usage up to this limit.

2. Request Counting: In ALS, a "request" typically refers to each API call made to the service. For geocoding, this would usually mean each call to the SearchPlaceIndexForText or GetPlace API. If you're only seeing about 100 requests, it's possible that your Lambda function is batching multiple addresses into single API calls, which could significantly reduce the number of billable requests.

3. Caching: Lambda functions don't inherently cache results between invocations. However, if your function is implemented to store and reuse results for repeated addresses, this could reduce the number of API calls made to ALS.

4. Console Interactions: The increase in request count when opening the Place Index configuration page is likely due to the console making API calls to retrieve and display the current configuration and usage statistics. This is normal behavior and separate from your Lambda function's usage.

5. Billing Delay: There can sometimes be a delay between when services are used and when usage appears in billing systems. It's possible that not all of your usage has been processed yet.

6. API Quotas: ALS has default quotas for different APIs. For example, the Geocode API has a default limit of 100 requests per second. If your Lambda function is making requests faster than this, some requests might be throttled or dropped, which could affect your total count.

Given the discrepancy between your expected usage (133,000 geocoding calls) and what you're seeing in the console (~100 requests), I would recommend the following:

1. Double-check your Lambda function code to ensure it's making individual API calls for each address and not batching them.
2. Verify that your function isn't implementing any caching mechanism.
3. Check your Lambda function logs for any errors or throttling messages.
4. Wait a few days to see if the usage statistics and billing information update.
5. If the discrepancy persists, consider opening a support ticket with AWS to investigate further.

Remember, it's crucial to monitor your usage closely, especially when working with large datasets, to avoid unexpected charges.
Sources
AWS Location Service Usage - Free Tier | AWS re:Post
Places quotas and usage - Amazon Location Service
Amazon Location Service Pricing – Amazon Web Services
Places pricing - Amazon Location Service